[Bibliometric and thematic analysis of the scientific literature about omega-3 fatty acids indexed in international databases on health sciences]. / Análisis bibliométrico y temático de la producción científica sobre ácidos grasos omega-3 indizada en las bases de datos internacionales sobre ciencias de la salud.

OBJECTIVE: To evaluate by bibliometric and thematic analysis the scientific literature on omega-3 fatty acids indexed in international databases on health sciences and to establish a comparative base for future analysis. METHOD: Searches were conducted with the descriptor (MeSH, as Major Topic) "Fatty Acids, Omega-3" from the first date available until December 31, 2010. Databases consulted: MEDLINE (via PubMed), EMBASE, ISI Web of Knowledge, CINAHL and LILACS. RESULTS: The most common type of document was originals articles. Obsolescence was set at 5 years. The geographical distribution of authors who appear as first author was EEUU and the articles were written predominantly in English. The study population was 90.98% (95% CI 89.25 to 92.71) adult humans. The documents were classified into 59 subject areas and the most studied topic 16.24% (95% CI 14.4 to 18.04) associated with omega-3, was cardiovascular disease. CONCLUSION: This study indicates that the scientific literature on omega-3 fatty acids is a full force area of knowledge. The Anglo-Saxon institutions dominate the scientific production and it is mainly oriented to the study of cardiovascular disease.

Modifications of gamma-glutamyl transpeptidase activity in duodenal mucosa of rats treated with different antiulcer drugs.

The activity of gamma-glutamyl transpeptidase (gamma-GT) in duodenal mucosa both in healthy rats and in rats experimentally ulcerated with indomethacin increases significantly after oral administration of pirenzepine as well as ranitidine but not after oral administration of sucralphate. These increase in gamma-GT activity may contribute to the cytoprotective effects already described for pirenzepine and ranitidine.

Circadian rhythms of food intake in gastroduodenally-ulcerated rats: effects of three anti-ulcer drugs.

The effects of three anti-ulcers drugs on the temporal distribution of food intake and of the two parameters, meal size and meal frequency, were studied in ulcerated and non-ulcerated rats exposed to light-dark (LD 12:12) cycles. Experimental ulceration with indomethacin reduces the amplitude of meal frequency and brings the acrophase forward, compared with non-ulcerated animals. These effects were reversed by the oral administration of either ranitidine, sucralfate or pirenzepine along with the food. However, the administration of either pirenzepine or sucralfate alone to non-ulcerated rats is accompanied by significant (P less than 0.05) changes in the circadian patterns of meal size and meal frequency without the total daily food intake being affected in any way (pirenzepine treatment caused large intake of food during the light period while sucralfate treatment resulted in marked food intake during the dark period). The results indicate that circadian modification of meal patterns in the ulcerated rats are attributable to indomethacin-induced gastrointestinal mucosal injury and anti-ulcer medications.

The influence of PTH, calcium gluconate and EDTA on the parotid saliva in the goat.

1. The role of exogenous parathyroid hormone (PTH) and stimulation or inhibition of endogenous hormone release, on the parotid gland of normal and thyroparathyroidectomized (t.x.p.t.x.) goats was studied. 2. The intravenous infusion of PTH and EDTA produced a transitory rise in saliva flow rate in intact animals. In t.x.p.t.x. goats the flow of saliva decreased transiently throughout the infusion. 3. The calcium levels in parotid saliva was unchanged throughout the infusion of PTH, EDTA, calcium gluconate both alone or with propranolol, in either intact or t.x.p.t.x. animals. 4. The parathyroid hormone infusion caused an increase in salivary phosphate concentration in both intact and operated goats. The effects of PTH upon the salivary flow and concentration of P are discussed.

Effect of the antimuscarinic agent pirenzepine on the in vivo biliary secretion of dogs in response to various stimuli.

Pirenzepine is known to be an antiulcer drug with antimuscarinic activity. The present work shows the effect of pirenzepine dihydrochloride on biliary secretion in dogs under normal conditions and after the application of different nervous and humoral stimuli. Pirenzepine (3 mg/kg) was orally administered to unanaesthetized dogs one hour before feeding. This treatment diminished the increase in biliary secretion as well as the intracholedochal pressure that usually followed feeding. On the other hand, a 0.75 mg/kg dose of the antimuscarinic drug intravenously administered to anaesthetized dogs, significantly reduced the increase in intracholedochal pressure produced after the injection of acetylcholine or cholecystokinin (CCK-PZ). Finally, the same dose of pirenzepine eliminated the effect of vagal electrical stimulation on intracholedochal pressure. These results suggest that the effect of pirenzepine on biliary secretion is mainly due to its action on the emptying of the gallbladder.

The influence of sympathomimetic and sympatholytic agents on the salivary flow rate and concentration of Ca, P and protein in the parotid gland of the goat.

1. The role of the sympathetic autonomic division on the parotid gland of normal and thyroparathyroidectomized (t.x.p.t.x.) goats was studied. 2. The salivary flow rate and concentration of Ca, P and protein was tested during the intravenous infusions of sympathomimetic and sympatholytic agents. 3. The intravenous infusion of isoprenaline modified the salivary flow rate and the concentration of total protein. 4. None of the tested drugs modified significantly the concentration of Ca and P in the parotid saliva. 5. The results obtained in normal and t.x.p.t.x animals were similar; it seems that PTH is not involved in the observed changes.

Influence of superior cervical ganglion stimulation frequency on salivary secretion in the rabbit. Comparative study of parotid and mandibular glands.

Saliva secretion in response to the stimulation of the superior cervical ganglion (S.C.G.) at different frequencies (2, 3, 5, 10, 15, 20 Hz) has been studied in anaesthetized rabbits. The differences between the two major glands in this species were analyzed, with respect to the flow response, potassium, amylase and total protein content during the sympathetic stimulation. The stimulation of S.C.G. increased the salivary flow rate at all frequencies, on both parotid and mandibular gland. In the parotid gland the flow and stimulation frequency show a positive linear correlation which does not appear in the mandibular gland. In conclusion, the differences observed in the response to sympathetic stimulation in both glands seem to be due to distinct patterns of sympathetic innervation on different glandular elements.

Surgical preparation for the study of pancreatic exocrine secretion in the conscious preruminant goat.

A new surgical procedure for the study of pancreatic secretion in the conscious preruminant goat, under conditions which approach physiological normality, is described. The bile and pancreatic juice retain their natural route and preserve the normal function of the sphincter of Oddi. Experiments could be started 3 days after surgery.

Effect of the histamine-H2 antagonist cimetidine on meal-stimulated biliary secretion in dogs.

In conscious dogs with a bidirectional biliary cannula we studied the effect of orally administered cimetidine (10 mg/kg) on biliary secretion in response to a standard meal. The intake of a meal induced a significant increase in the biliary flow. When cimetidine is administered before feeding, a greater biliary response was observed in both cholecystectomized and uncholecystectomized animals. Under our experimental conditions this effect could be explained by an increase in the resistance of the sphincter of Oddi together with an increase in biliary tract and gallbladder motility. On the other hand, decrease in taurocholate and increase in chloride concentrations were observed during cimetidine treatment in all dogs. Moreover cimetidine elicits a fall in bilirubin concentration in cholecystectomized animals. The changes in organic anions could be due to a reduction in portal blood flow together with an interference of cimetidine with hepatic oxidative pathways. The greater concentration of chloride could be due to a lesser release of secretin. Most of these effects were transitory because they return to control values after the end of treatment.

A comparative study of salivary secretion by parotid and mandibular glands of anaesthetized Capra hircus: effect of pilocarpine.

A study was made of basal secretion and the effect of the infusion of pilocarpine on the flow and composition of saliva in the parotid and mandibular glands of the anaesthetized lactating goat. In the parotid gland there was a basal flow (1.6 +/- 0.29 microliter/min) which was not present in the mandibular gland. There is a statistically significant dose-effect relationship between pilocarpine and salivary flow in both glands. Salival composition and its variation with respect to the flow of saliva did not conform to either of the two glands to an exclusive monogastric or ruminant model.

Cimetidine and postprandial pancreatic exocrine secretion in dogs.

In dogs fitted with a pancreatic cannula and a duodenal cannula the intake of a standard meal induced a significant increase in the flow of pancreatic secretion and in the output of amylase, total protein, bicarbonate and chloride. The oral administration (200 mg/day) of cimetidine to dogs was seen to elicit a marked decrease in postprandial flow increase and bicarbonate output, coinciding with a significant increase in amylase and total protein output. At the same time the postprandial duodenal pH remained at levels similar to those obtained in basal periods. The implications of secretin, gastrin and cholecystokinin (CCK) on these effects are discussed.

Biliary secretion in the conscious preruminant goat: use of a re-entrant cannula.

A double re-entrant bile cannula is described for use in conscious goats which permits study of bile flow and composition.

Postprandial pancreatic exocrine secretion in dogs after oral administration of pirenzepine dihydrochloride.

The effect of orally administered 1,5-dihydroxy-11-(4-methyl-1-piperazinyl)- acetyl-6H-pyrido[2,3-b]-1,4-benzodiazepin-6-one dihydrochloride (pirenzepine dihydrochloride, LS-519 Cl, Gastrozepin) on the postprandial secretion of pancreatic juice and the duodenal pH was studied in conscious dogs. An inhibition of the normal increase of the postprandial pancreatic secretion was observed. A possible indirect role of endogenous secretin and a cholinergic enteropancreatic reflex was discussed.

Role of alpha and beta adrenoceptors on the salivary secretion in the mandibular gland of the rabbit.

The stimulation of the superior cervical ganglion increased the salivary flow rate (about five-fold) in all 35 rabbits studied but two. The administration of alpha or beta adrenoceptor blocking drugs was unable to eliminate the positive effect of the sympathetic stimulation on the salivary flow, though the flow rate fell about 50% with the administration of each of the blockers. According to these results both types of receptors may be involved in the secretory response of this gland. Nevertheless it seems that the beta-adrenoceptors play a more important role in the secretory response and the alpha-adrenoceptors in the motor one.

Effect of sympathetic stimulation on salivary secretion in submandibular gland in the rabbit stimulated by pilocarpine.

The sympathetic stimulation under slow pilocarpine-induced flow conditions brought about a decrease in this flow rate that could be due to vasoconstriction, since such an effect was not observed after the administration of phentolamine (4 mg/kg i.v.). Contrariwise the injection of a beta-adrenergic blocking agent (propranolol 2-2.5 mg/kg i.v.) produced a decrease of the salivary flow rate that was even greater than in the control animals. These results suggest that the secretory effect in this gland and species is predominantly beta-adrenergic. The stated results are related to the changes observed in the blood outflow from the gland.

Use of a bidirectional cannula to study biliary secretion in conscious dogs.

A new biliary bidirectional cannula is described which allows the study of biliary secretion in conscious dogs under conditions which approach physiological normality.

[Sympathetic control on salivary secretion by the parotid gland in rabbit. I. Effects on the unstimulated gland (author's transl)]. / Influencias simpáticas sobre la secreción de saliva por la parótida del conejo I. Efectos sobre la glándula en reposo.

The sympathetic influences on the rabbit unstimulated parotid gland were studied. The experiments were carried out in anaesthetized rabbits with the Stenon aduct cannulated. Direct stimulation of the superior cervical ganglion elicits variable salivary flows. The high amylase content in the saliva points to a sympathetic secretory action upon acinar cells. The administration of alpha-adrenergic blocking agents (dihydroergotamine, phentolamine and phenoxybenzamine) clearly reduces and even abolishes the effect of the sympathetic stimulation upon flow. The administration of a beta-adrenergic blocking agent (propranolol) slightly reduces the sympathetic action. However the amylase activity is greatly reduced. All this suggests that the secretory effects on the fluid fraction should predominantly be alpha-adrenergic while on the secretion of enzymes the beta-receptors should play an important role.

[Sympathetic control on salivary secretion by the parotid gland in rabbit. II. Effects upon the gland submitted to a weak parasympathetic stimulation (author's transl)]. / Influencias simpáticas sobre la secreción de saliva por la parótida del conejo II. Efectos sobre la glándula sometida a estimulación parasimpática débil.

Superior cervical ganglion stimulation significantly increases both, flow and amylase activity of saliva. Stimulation provokes two markedly different periods of flow: during the first half, flow is very high and differs significantly from the flow of the second half which closely resembles the one previous to stimulation. Alpha-adrenergic blocking agents, when administered intravenously, abolish the hypersecretion induced by sympathetic stimulation; beta-adrenergic blocking agents do not. These facts strengthen the hypothesis that alpha-adrenoceptors are most important in fluid secretion. The infusion of epinephrine acts similarly on cervical ganglion stimulation, but it differs because of its more diffuse effects and deeper cardiovascular alterations. Isoproterenol, after a long latency period, slightly increases salivary flow, which seemingly indicates that beta-adrenoceptors are involved in the fluid secretory processes although in a lesser degree than alpha-adrenoceptors.